Power management circuitry in peripheral accessories of audio devices

ABSTRACT

A power management circuitry for a peripheral electronic device includes a power regeneration circuitry, a power selector, a power switch and an audio signal detection circuitry. The power regeneration circuitry receives a continuous periodic sound wave from an audio device and converts the continuous periodic sound wave into an amplified DC electrical signal. The power source selector receives the amplified DC electrical signal and input from a primary power source and provides a power signal output. The audio signal detection circuitry receives the amplified DC electrical signal and transmits a wake-up signal to the power switch circuitry. The power switch circuitry is turned on by the wake-up signal and connects the power source selector to the peripheral electronic device main circuitry and transfers the power signal output to the peripheral electronic device main circuitry.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/284,174, filed Feb. 25, 2019, entitled POWER MANAGEMENT CIRCUITRY INPERIPHERAL ACCESSORIES OF AUDIO DEVICES (Atty. Dkt. No. BBPS60-34524),which is a continuation of U.S. patent application Ser. No. 15/726,262,filed on Oct. 5, 2017, entitled POWER MANAGEMENT CIRCUITRY IN PERIPHERALACCESSORIES OF AUDIO DEVICES, which issued on Apr. 9, 2019 as U.S. Pat.No. 10,256,627. U.S. application Ser. No. 15/726,262 is a continuationof U.S. patent application Ser. No. 14/491,306, filed on Sep. 19, 2014,entitled POWER MANAGEMENT CIRCUITRY IN PERIPHERAL ACCESSORIES OF AUDIODEVICES, which issued on Oct. 17, 2017 as U.S. Pat. No. 9,793,712. U.S.application Ser. No. 14/491,306 is a continuation of U.S. patentapplication Ser. No. 13/562,501, filed Jul. 31, 2012 and entitled POWERMANAGEMENT CIRCUITRY IN PERIPHERAL ACCESSORIES OF AUDIO DEVICES, whichissued on Sep. 23, 2014 as U.S. Pat. No. 8,840,017. U.S. patentapplication Ser. No. 13/562,501 is a continuation in part and claims thebenefit of U.S. application Ser. No. 12/767,831, filed Apr. 27, 2010 andentitled DEBIT AND CREDIT CARD TRANSACTION DEVICE, which issued on Dec.25, 2012 as U.S. Pat. No. 8,336,771. U.S. patent application Ser. Nos.16/284,174, 15/726,262, 14/491,306, 13/562,501 and 12/767,831, and U.S.Pat. Nos. 10,256,627, 9,793,712, 8,840,017, and 8,336,771 areincorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to power management circuitry inperipheral accessories of audio devices, and in particular to powermanagement circuitry that regenerates power in a peripheral accessoryfrom an audio device.

BACKGROUND

Portable personal computing devices such as smart phones, PersonalDigital Assistant (PDA), portable computers, tablet computers and audiodevices such as digital music players have become ubiquitous in recentyears. These devices usually have different built-in physical electricalinterfaces such as USB, FireWire, RS232 serial port and audio plug,among others. In almost all of these devices, and in particular in theaudio devices, the audio plug is a common interface. The audio plug of adevice acts as a receptacle for an audio jack connector which is usedfor transmitting analog signals including audio signals. The audio plugis used to connect to headphones, speakers, microphones, and hands-freedevices, among others.

In the past, many mobile phones used to have their own proprietary formof audio plugs configured to be used with cables outfitted with matchingproprietary audio jacks. However, recently the functionality of mobilephones has changed so much that most mobile phones are now also digitalmusic players, payment devices, navigation devices and cameras, amongothers. Additional accessory devices including headphones, printers, andcard readers, among others, may be connected to the mobile phones inorder listen to music, print and complete payments, among others.Therefore due to these added functionalities and the need to connectadditional accessory devices to mobile phones, 2.5 mm audio plugs and/or3.5 mm audio plugs can now be found on most middle to high-end mobilephones.

Several electronic peripheral accessories for mobile devices may use theaudio plug interface as the signal interface and all these accessorieshave electronic circuitry that requires power to function. Theelectrical power may come either from the mobile device or from aninternal battery placed inside the peripheral accessory. In some cases,the internal battery is not replaceable because the compartment of theaccessory is glued, sealed or otherwise permanently put together and isnot intended to be opened up for battery replacement. Thus, there is aneed to manage the power consumption in the peripheral accessory inorder to prolong the battery lifetime of the internal battery.

SUMMARY

This present invention provides a device and a method for increasing thebattery lifetime of a peripheral accessory by connecting the peripheralaccessory to a secondary external power source via an audio jackconnector. The device includes a power management circuitry that detectsthe presence of an audio power source and generates an electrical signalthat is used to turn on a power switch of the accessory. The device alsoincludes a power source selector that provides power to the peripheralaccessory either from the internal battery or from the secondaryexternal power source. The circuitry also enables the internal batteryto be charged by the secondary external power source.

In general, in one aspect the invention provides a power managementcircuitry that is used in a peripheral electronic device. The powermanagement circuitry includes a power regeneration circuitry, a powerselector, a power switch and an audio signal detection circuitry. Thepower regeneration circuitry is configured to receive a continuousperiodic sound wave from an audio device and to convert the continuousperiodic sound wave into an amplified DC electrical signal. The powersource selector is configured to receive a first input comprising theamplified DC electrical signal from the power regeneration circuitry anda second input from a primary power source and to provide a power signaloutput. The audio signal detection circuitry is configured to receivethe amplified DC electrical signal from the power regeneration circuitryand to transmit a wake-up signal to the power switch circuitry. Thepower switch circuitry is configured to be turned on by the wake-upsignal and to connect the power source selector to the peripheralelectronic device main circuitry and thereby to transfer the powersignal output to the peripheral electronic device main circuitry.

Implementations of this aspect of the invention may include one or moreof the following features. The power management circuitry of claim mayfurther include an audio jack connector configured to connect theperipheral electronic device to the audio device. The audio devicecomprises a secondary power source and is configured to transmit thecontinuous periodic sound wave to the power management circuitry. Theprimary power source may be a battery, a capacitor, a rechargeable powersource or a non-rechargeable power source. The secondary power sourcemay be a battery, a capacitor, a solar cell, a circuitry thatregenerates power from an audio signal, a thermoelectric generator, apiezoelectric element, a device that generates power from motion andvibration, a rechargeable power source or a non-rechargeable powersource. The audio jack connector includes a ground (GND) contact, amicrophone-in (MIC-IN) contact and one or more earphone channelcontacts. The audio jack may be a 4-contact Tip-Ring-Ring-Sleeve (TRRS)connector, 3-contact Tip-Ring-Sleeve (TRS) connector, a 3.5 mm audiojack, a 6.35 mm audio jack, a 2.5 mm audio jack, RCA connector, XLRconnector, a banana connector, mono or stereo versions thereof. Theaudio device includes an audio plug configured to receive the audio jackconnector and the audio plug comprises a ground (GND) contact configuredto connect to the audio jack GND contact, a microphone-in (MIC-IN)contact configured to connect to the audio jack MIC-IN contact and oneor more earphone channel contacts configured to connect to the audiojack one or more earphone channel contacts, respectively. The primarypower source is configured to be recharged by the secondary power sourcevia the power regeneration circuitry. The power regeneration circuitrymay be a voltage multiplier or a transformer. The power regenerationcircuitry may further include a voltage stabilizer and power storage.The continuous period sound wave may be a sinusoidal in-phase soundwaves played in left and right channels of the audio device, asinusoidal out-of-phase sound waves played in left and right channels ofthe audio device, a square in-phase sound waves played in left and rightchannels of the audio device, or a square out-of-phase sound wavesplayed in left and right channels of the audio device. The audio devicemay be a mobile phone, a personal digital assistant (PDA), netbook,tablet computer, notebook computer, game console, e-book reader,portable video player, or digital audio player. The peripheralelectronic device may be a payment card reader, magnetic card reader, aprinter, headphones, speakers, microphones, or hands-free versionsthereof.

In general, in another aspect, the invention features a method forproviding power management in a peripheral electronic device. The methodincludes providing a power regeneration circuitry configured to receivea continuous periodic sound wave from an audio device and to convert thecontinuous periodic sound wave into an amplified DC electrical signal.Next, providing a power source selector configured to receive a firstinput comprising the amplified DC electrical signal from the powerregeneration circuitry and a second input from a primary power sourceand to provide a power signal output, Next, providing a power switchcircuitry. Next, providing an audio signal detection circuitryconfigured to receive the amplified DC electrical signal from the powerregeneration circuitry and to transmit a wake-up signal to the powerswitch circuitry. The power switch circuitry is configured to be turnedon by the wake-up signal and to connect the power source selector to theperipheral electronic device main circuitry and thereby to transfer thepower signal output to the peripheral electronic device main circuitry

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview diagram of a peripheral device connecting to anaudio device via an audio jack;

FIG. 2 is a block diagram of the circuitry of the peripheral device ofFIG. 1;

FIG. 3 is a block diagram of one embodiment of a peripheral device ofFIG. 1;

FIG. 4 is one embodiment of the power regeneration circuitry of FIG. 2;

FIG. 5 is another embodiment of the power regeneration circuitry of FIG.2;

FIG. 6 is another embodiment of the power regeneration circuitry of FIG.2;

FIG. 7A depicts continuous sinusoidal out-of-phase sound waves played inthe left and right channels of the audio device of FIG. 1;

FIG. 7B depicts a continuous square out-of-phase sound wave played inthe left and right channels of the audio device of FIG. 1;

FIG. 8A depicts a continuous sinusoidal in-phase sound wave played inthe left and right channels of the audio device of FIG. 1

FIG. 8B depicts a continuous square in-phase sound wave played in theleft and right channels of the audio device of FIG. 1;

FIG. 9 depicts a schematic diagram of an audio jack of the peripheraldevice of FIG. 1;

and

FIG. 10 depicts a schematic diagram of an audio plug of the audio deviceof FIG. 1.

DETAILED DESCRIPTION

Several electronic peripheral accessories for mobile devices use theaudio plug interface as the signal interface. All of these peripheralaccessories have electronic circuitry that requires power to function.The electrical power may come either from the mobile device or from aninternal battery placed inside the peripheral accessory. In some cases,the internal battery is not replaceable because the compartment of theaccessory is glued, sealed or otherwise permanently put together and isnot intended to be opened up for battery replacement. Thus, there is aneed to prolong the battery lifetime of the internal battery in theperipheral accessory. In the present invention, this is achieved bycompletely cutting off the battery from the circuitry, and/or by using asecondary external power source, and/or by recharging the internalbattery from an external power source.

In an electronic device that does not have a hard power switch that cutsthe power circuitry off completely, the electronic circuitry is actuallystill working with the controller running in some low-power modes. Inthis invention, a passive detection circuitry is used to detect thepresence of the mobile device by detecting signals from the audio jack.The internal battery is completely cut off from the main circuitry by apower switch circuitry and then it is switched on by the detectioncircuitry. When an audio signal is detected, electric power isregenerated from the audio signal to turn on the main circuitryincluding the microcontroller and the rest of the circuitry.

The invention provides a power source selector that can select powereither from the internal battery or a secondary external power source.If the secondary source can provide the required power, no power will bedrawn from the internal battery. The internal battery will only be usedto supply the power if the secondary source does not meet the powerconsumption required by the peripheral accessory. The secondary powersource may be any power source such as a battery, a capacitor, a solarcell, a thermoelectric generator, piezoelectric element, or a componentthat generates power from motion and vibration, among others. In oneembodiment, the secondary source provides power regenerated from theaudio signal through the audio jack. The power from the mobile device isused to power up the accessory while data can be communicated betweenthe mobile device and the accessory at the same time.

The present invention also provides a method for recharging the internalrechargeable battery (or other rechargeable power storage element suchas a capacitor) by the secondary source. In one embodiment, the powerregenerated from the audio signal can be used to recharge the internalbattery.

Some mobile devices do not have enough audio output to supply therequired power. The presence of the internal power source and thesecondary power source enable those mobile devices to work with theaccessory as well. Therefore, the invention allows a peripheralaccessory to be used with a much wider range of devices.

Referring to FIG. 1, peripheral accessory device 100 includes a powermanagement circuit 200 and an audio jack connector 101. Peripheralaccessory device 100 connects to a mobile audio device 110 by insertingthe audio jack connector 101 into the mobile audio device's audio plug111. Audio plug 111 includes four contact points 116, 117, 118 and 119,shown in FIG. 10. Normally, contact points 118 and 119 are connected tothe right channel (R-CH) and left channel (L-CH) of the stereo audiooutput of the mobile audio device, respectively. In some models ofmobile audio devices, contact point 117 is connected to the ground (GND)and contact point 116 is connected to the microphone-in (MIC-IN) of themobile audio device. In other models of the mobile audio device, contactpoint 117 is connected to MIC-IN and contact point 116 is connected toGND. Therefore, there are two possible arrangements of the contactpoints of MIC-IN and GND of the mobile audio device plug.

In one example, audio jack connector 101 has the form of a 4-contactTip-Ring-Ring-Sleeve (TRRS) connector, shown in FIG. 9. Audio jack 101includes microphone-in (MIC-IN) contact 110, GND contact 111, R-CHcontact 112, L-CH contact 113 and insulating rings 114. In otherexamples, audio jack connector 101 has the form of a 3-contactTip-Ring-Sleeve (TRS) connector used with monaural audio devices. The3.5 mm audio jack is used for illustration purposes only. In otherexamples, audio jack connectors are TRS connector 6.35 mm (quarter inch)jacks, 2.5 mm (subminiature) jacks, both mono and stereo versions of theabove mentioned jacks, RCA connectors, XLR connectors, or bananaconnectors, among others.

The mobile audio device 110 may be a mobile phone, a personal digitalassistant (PDA), netbook, tablet computer, notebook computer, gameconsole, e-book reader, portable video player, digital audio player,among others. In one example, peripheral accessory 100 includes inaddition to the audio jack connector 101 and the power managementcircuit 200, a magnetic card reader 102, and a microprocessor or microcontroller unit (MCV), shown in FIG. 3

Referring to FIG. 2, power management circuitry 200 includes a powerregeneration circuitry 210, a power source selector 240, an audio signaldetection circuitry 220, a power switch circuitry 230 and the maincircuitry 260. Mobile audio device 110 is programmed to play a periodicsound wave continuously. Examples of the continuous period sound wavesinclude continuous sinusoidal out-of-phase sound waves played in theleft and right channels 181, 182 of the audio device 110, shown in FIG.7A, continuous sinusoidal in-phase sound waves played in the left andright channels 185, 186 of the audio device 110, shown in FIG. 8A,continuous square out-of-phase sound waves played in the left and rightchannels 183, 184 of the audio device 110, shown in FIG. 7B, andcontinuous square in-phase sound waves played in the left and rightchannels 187, 188 of the audio device 110, shown in FIG. 8B.

When the peripheral accessory 100 is plugged into the audio device 110and the audio device 110 generates and transmits an audio signal to theperipheral accessory 100 via the audio jack 101, the signal 201 from oneof the contacts 203 is fed into the power regeneration circuitry 210.From the power regeneration circuitry 210 input side, the periodic soundwave signal 201 looks like an AC power signal with a very low voltage.The power regeneration circuitry 210 receives the audio signal 201 andgenerates a stable DC electrical signal 211 with an increased voltage.The generated DC electrical signal 211 is then fed into the audio signaldetection circuitry 220. The power regeneration circuitry 210 alsogenerates a regenerated power signal 212 which is fed into the input ofthe power selector 240. Power selector 240 also receives an input 251from the internal battery 250. The output 241 of the power selector 240originates either from the internal battery 250 or is the power signal212 that originates from the external source 110.

The power regeneration circuitry 210 uses either a voltage multiplier ora transformer in order to increase the voltage of the input signal 201and to generate a stable DC electrical signal 211. Referring to FIG. 4,in one embodiment, the power regeneration circuitry 210 receives inputs150,151, from the left and right earphone channels 181, 182 of the audiodevice 110, respectively and generates a DC electrical signal (VCCoutput) 163. In one example, input signals 150, 151 are 5 kHzout-of-phase sine or square waves, shown in FIGS. 7A and 7B,respectively. The power regeneration circuitry 210 includes four smallcapacitors 153, 156, 157, 159, four diodes 154, 155, 158, 160 and onelarger capacitor 161. In one example, small capacitors 153, 156, 157,159 are 22 μF capacitors, diodes 154, 155, 158, 160 are low voltageSchottky diodes, and larger capacitor 161 is a 1000 μF capacitor. Diodes154, 155 and capacitors 153, 156 form a voltage doubling circuit thatconverts the input signal 201 from AC to DC and doubles the inputvoltage. Diodes 158, 160 and capacitors 157, 159 form another voltagedoubling circuit that further doubles the input voltage. After the twovoltage doubling steps the output voltage is a DC voltage with a fourtimes amplified amplitude. The larger capacitor 161, stabilizes the DCoutput signal and stores power. When the continuous sound wave isstopped, capacitor 161 provides power to the device in order to finishongoing operations. In the embodiment of FIG. 5, the operation of thepower regeneration circuitry 210 is the same as in the embodiment ofFIG. 4, except that the input signals are in-phase continuous sine orsquare waves, as shown in FIG. 8A, and FIG. 8B.

Referring to FIG. 6, in another embodiment, the power regenerationcircuitry 210 receives inputs 150, 151, from the left and right earphonechannels 181, 182 of the audio device 110, respectively and generates aDC electrical signal (VCC output) 177. In one example, input signals150, 151 are 5 kHz out-of-phase sine or square waves, shown in FIGS. 7Aand 7B, respectively. The power regeneration circuitry 210 includes atransformer 170, four diodes 171, 172, 173, 174 and one large capacitor175. In one example, transformer 170 has a primary winding impedance of16 ohm at 5 kHz sine wave, diodes 154, 155, 158, 160 are low voltageSchottky diodes, and large capacitor 175 is a 1000 μF capacitor. Thetransformer amplifies the input AC voltage by 10 times and the fourdiodes 171,172,173,174 form a bridge circuit that converts the signalfrom AC to DC. The large capacitor 175, stabilizes the DC output signaland stores power. When the continuous sound wave is stopped, capacitor175 provides power to the device in order to finish ongoing operations.

In other embodiments, the voltage multiplier is a 3-stage or morevoltage doubler. In one example, the peak-to-peak AC voltage output froma weak audio device or phone 110 is 0.3 V and the operating voltage ofthe magnetic card reader 102 is 2.3V. In this case a 3-stage multiplieris used to multiply the AC input voltage by 8 times and thereby toincrease the signal to 2.4V (0.3V times 8). In another example, thepeak-to-peak AC voltage output from a strong audio device or phone 110is 1 V and the operating voltage of the magnetic card reader 102 is2.3V. In this case the 3-stage multiplier multiplies the AC inputvoltage by 8 times and generates a signal of 8V (1 V times 8). Thisvoltage output is too strong and will destroy the magnetic card reader102. Therefore, a Zener diode (not shown) is used to limit the outputvoltage to 2.4 V. In summary, the voltage regeneration circuitry 210 isa voltage multiplier or transformer that multiplies the AC input signalthat originates from a continuous periodic sound wave emitted by theaudio device 110. The voltage regeneration circuitry 210 also convertsthe AC signal into a DC signal and limits the voltage of the outputsignal to the operating voltage level of the peripheral accessorydevice.

As was mentioned above, audio signal 201 originating from the MIC-INcontact 203 is converted into a DC electrical signal 211 and the DCelectrical signal 211 is used to switch on the power for the audiosignal detection circuitry 220, which draws power from the internalbattery 250. Once the audio detection circuitry 220 detects the presenceof signal 211, it sends a signal 221 that turns on the power switchcircuitry 230. Power switch circuitry 230, then transmits the powersupply output of the power selector 240 to the main circuitry 260.

Several embodiments of the present invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. A power management circuitry for a peripheralelectronic device comprising: a power regeneration circuitry to receivea periodic sound wave from a mobile audio device and to generate a firstoutput and a second output, wherein: the first output comprises aregenerated power signal, and the second output comprises an amplifiedDC electrical signal produced based on the periodic sound wave; a powersource selector to: receive a first input comprising the first outputgenerated by the power regeneration circuitry, and receive a secondinput from a primary power source, and provide a power signal outputbased on the first and second inputs; a power switch circuitry; an audiosignal detection circuitry to: detect the second output from the powerregeneration circuitry, and transmit a wake-up signal to the powerswitch circuitry based on the detection; the power switch circuitry isturned on by the wake-up signal; and the power switch circuitry couplesthe power source selector to a main circuitry of the peripheralelectronic device, and thereby transfers the power signal output to themain circuitry of the peripheral electronic device.
 2. A method forproviding power management in a peripheral electronic device comprising:enabling a power regeneration circuitry to: receive a periodic soundwave from a mobile audio device, convert the periodic sound wave into afirst output signal comprising an amplified DC electrical signal, andproduce, based on the periodic sound wave, a second output signalcomprising a regenerated power signal; enabling a power source selectorto: receive a first input comprising the second output signal from thepower regeneration circuitry and a second input from a primary powersource, and produce a power signal output; providing a power switchcircuitry; enabling an audio signal detection circuitry to: detect thefirst output signal from the power regeneration circuitry, and transmita wake-up signal to the power switch circuitry based on the detection,wherein the transmitted wake-up signal turns on the power switchcircuitry; and the power switch circuitry connects the power sourceselector to a main circuitry the peripheral electronic device, andthereby transfers the power signal output to the main circuitry of theperipheral electronic device.
 3. A power management circuitry used in aperipheral electronic device comprising: a power regeneration circuitryto receive a periodic sound wave from a mobile audio device, and producean amplified DC electrical signal and a regenerated power signal basedon the received periodic sound wave; a power switch circuitry; an audiosignal detection circuitry to detect the amplified DC electrical signaland to transmit a wake-up signal to the power switch circuitry based onthe detection; the power switch circuitry is turned on by the wake-upsignal; and the power switch circuitry couples the power regenerationcircuitry to a main circuitry of the peripheral electronic device andthereby transfers the regenerated power signal to the main circuitry ofthe peripheral electronic device.